## Collecting Bills

• 문제 ID
• 시간 제한
• 메모리 제한
• 제출 횟수
• 정답 횟수 (비율)
• 출처
• 분류

#### 문제

After being retired from ACM-ICPC, Mr. R decided to quit studying computer science to become a farmer. This year, he harvested N$N$ cabbages, and the price of one cabbage is K$K$ won. R wants to sell all of these cabbages to the Farm Co-Op, but the Farm Co-Op has a rather complicated purchasing policy:

1. R can split the cabbages into any number of bunches, and sell them separately.
2. Every time R cells a bunch of cabbages, he has two ways to collect his earnings:
1. He can get a check: however, checks can be issued only for amounts multiple of 10,000 won, and the remaining money will be thrown away.
2. He can get the money wired to his bank account: however, the bank will take 10% as transaction fee and round down the remaining money to the nearest won.

So, how much money can Mr.R can get at most by selling all of the cabbages?

#### 입력

The first line of the input file will contain the number of test cases, C$C$. Each line consists of two integers, N$N$ and K$K$.

• C \le 1,000$C \le 1,000$
• 1 \le N \le 100,000,000$1 \le N \le 100,000,000$
• 1 \le K \le 100,000,000$1 \le K \le 100,000,000$
• K \times N \le 2^{31}-1$K \times N \le 2^{31}-1$

#### 출력

For each test case, print the maximum amount of money Mr.R can get.

#### 예제 입력

4
10000 1
9999 1
4 9800
4 2700

#### 예제 출력

10000
8999
35280
10000